1. Field of the Invention
The invention relates to a crankshaft bearing of an internal combustion engine.
2. Description of the Related Art
In a cylinder block of an internal combustion engine of an automobile, when a load is applied in a direction orthogonal to a longitudinal direction of the cylinder block, bending deformation occurs and a degree of concentricity of bearing metal fitting holes in journal bearing portions and a degree of concentricity of bearing metal holes are reduced (as described, for example, in Japanese Patent Laid-Open Publication No. 9-269004). Bearing metal fitting holes in all journal bearing portions may be mechanically processed in a cylinder block alone before a cylinder head and a cylinder head gasket are mounted on the cylinder block so that the bearing metal fitting holes in all the journal bearing portions become concentric. In this case, when the cylinder head gasket and the cylinder head are mounted, a degree of concentricity of the bearing metal fitting holes and a degree of concentricity of bearing metal holes are reduced due to elastic deformation of the cylinder block. Accordingly, friction that occurs when the crankshaft rotates becomes extremely large depending on a degree of reduction in the degree of concentricity.